Implement Soroban read-only contract calls: getEscrowInfo, getBalance, getProgramInfo, getRemainingBalance

[Jagadeeshftw]

📌 Description

In internal/soroban/escrow.go the read-only methods GetEscrowInfo/getEscrowInfoRPC and GetBalance/getBalanceRPC are stubs that log a warning and return without real data; the same is true for GetProgramInfo/getProgramInfoRPC and GetRemainingBalance/getRemainingBalanceRPC in internal/soroban/program.go. They never decode the contract return value from a simulation. Any payout flow that needs to read on-chain escrow state has nothing to call.

💡 Why it matters: Without working read paths, the backend cannot verify on-chain escrow/program balances before or after writes, undermining the payout lifecycle.

🧩 Requirements and context

• Implement the read paths using SimulateTransaction against the escrow/program contracts and decode the returned ScVal via the helpers in internal/soroban/xdr_helpers.go.
• Return typed Go structs for escrow info, balance, program info, and remaining balance.
• Propagate context and the existing 30s HTTP timeout; return clear errors instead of logging-and-returning-empty.
• Add unit tests decoding representative simulation responses (mock RPC).
• Keep write paths (Init/Lock/Release/Refund/Payout) unchanged.

Non-functional requirements

• Must be secure, tested, and documented.
• Should be efficient and easy to review.

🛠️ Suggested execution

1. Fork the repo and create a branch

git checkout -b feat/soroban-readonly-calls

2. Implement changes

• Write/modify the relevant source: internal/soroban/escrow.go, internal/soroban/program.go, possibly internal/soroban/rpc.go
• Write comprehensive tests: internal/soroban/escrow_test.go, internal/soroban/program_test.go
• Add documentation: GoDoc on the new return types
• Include GoDoc comments explaining ScVal decoding
• Validate security assumptions: treat simulation results as untrusted; validate types before decoding

3. Test and commit

• Run tests:

go test ./internal/soroban/...

• Cover edge cases: empty result, unexpected ScVal type, RPC error
• Include test output and security notes in the PR description.

Example commit message

feat(soroban): implement read-only escrow/program contract calls

✅ Acceptance criteria

• All four read methods return decoded data, not stub warnings
• Context and timeout propagated; errors surfaced
• ScVal decoding covered by unit tests with mock RPC
• Write paths unchanged

🔒 Security notes

Simulation output is attacker-influenceable on a public RPC; validate every decoded field and never trust length/type without checks.

📋 Guidelines

• Minimum 95% test coverage
• Clear documentation
• Timeframe: 96 hours

[mxrtins04]

Please can i be assigned this issue?